Shuttleless weaving



July 30, 1968 J. R. WHITE SHUTTLELESS WEAVING Filed Oct. 4, 1966 big 0 ggl y reocea Wm ATToR NE ys 3,394,740 SHUTTLELESS WEAVING John Roger White, Parbold, near Wigan, England, as-

signor t Carrington & Dewhurst Limited, a British company Filed Oct. 4, 1966, Ser. No. 584,242 14 Claims. (Cl. 139127) ABSTRACT OF THE DISCLOSURE A method of weaving wherein each weft pick is formed by projecting a thread through a warp shed by a carrier jet of a fluid wherein a pellet is first attached to the leading end of each weft thread in which each pellet is produced by extruding a tube of plastic material of low elasticity around the weft thread and substantially deforming the tube inwardly against the thread.

This invention relates to weaving, and in particular to the method of weaving wherein the weft yarn is impelled through the warp shed by means of a jet of fluid, such as air or water, the function of which is primarily to impart velocity to the yarn at its leading end, to carry it across the width of the shed. The efficiency achieved by this means is limited, but it is known to attach a pellet to the end of the weft yarn to increase the efiiciency by providing an impact area for the jet and thereafter making use of the momentum thus imparted to the pellet.

The main disadvantages of the method aforesaid are the problems of attaching the pellet to the end of the yarn, the disposal or re-use of the pellet or pellet material, and many other inherent problems some of which are now appreciated though only partly solved.

For example, it has been proposed to use a metal of low melting point, such as Linotype metals for the formation'of the pellets, but whilst the character of such metal makes it suitable for attachment to most textile yarns, its mass and/or elasticity introduce problems relating to its deceleration since some fine yarns can be damaged by tension if used to decelerate the pellet while its elasticity causes it to rebound if allowed to impact against some target. Re-use of the metal, for reasons of economy, is not too difficult though necessarily involving obvious problems.

It is an object of the present invention to provide an improved method of, and means for weaving, using a fluid-carried weft yarn.

The present invention comprises the method of weaving wherein each weft pick is formed by projecting a thread through a warp shed by a carrier jet of a fluid and wherein a pellet is first attached to the leading end of each weft thread, and is characterised in that each said pellet is produced by extruding a tube of material having plastic properties and low elasticity around the weft thread and subsequently deforming the tube inwardly against the thread.

The invention also includes apparatus for carrying out the method aforesaid.

The invention will be further apparent from the following description with reference to the single figure of the accompanying drawing, which shows, by way of example only, an axial section through one form of yarn projecting unit embodying the invention.

Referring now to the drawing it will be seen that the unit includes a barrel generally indicated by the reference numeral 10. The unit is adapted to be securely mounted at the side of a loom such that the barrel is aimed transversely through the warp shed formed on the loom by separation of two warp sheets by means of healds in known manner.

' United States Patent 0 3,394,740 Patented July 30, 1968 The barrel 10 is connected at its rear end with a block assembly generally indicated by the reference numeral 11 built up from several separate parts, as can clearly be seen on the drawing. The block assembly 11 is provided with a bore 12 through which a suitable material of low elasticity and having plastic properties, for example paraffin wax, is forced under pressure by means of a piston 12a into a chamber 13. The chamber 13 is of generally conical shape presenting an annular orifice at its forward end through which the material is extruded in the form of a tube forwardly towards the bore of the barrel 10.

The Weft yarn which is to be projected by the unit through the warp shed is derived from a suitable package thereof and enters the block assembly 11 through an aperture 14 which extends forwardly to a position communicating centrally with the bore of the barrel 10 at the rear thereof.

The block assembly 11 includes a further chamber 15 which communicates with the bore of the barrel 10 at the rear thereof through an annular orifice which surrounds the annular orifice of the chamber 13 and the forward end of the aperture 14. The chamber 15 is adapted to be connected with a source of high pressure air by means of a bore 16 extending through the block assembly 11.

Immediately before and adjacent the orifices to the chambers 13 and 16 are oppositely disposed hemispherical cavities 17 and 18. The lower cavity 18 is fixed in position such that its diametral plane is tangential to the bore of the barrel 10. The upper cavity 17 is formed at the end of a plunger 19 which is adapted for movement by means of an actuating rocker arm 20 between a first position wherein it is spaced from the cavity 18 by a distance at least equal to the diameter of the bore of the barrel 10 and a second position wherein it engages the cavity 18 such that a spherical die-cavity is formed. An ejector pin 21 extends through the plunger 19 and is urged upwardly by a compression spring 22 located in the bore in the plunger 19 and operative between the lower end of such bore and the underside of an enlarged diameter portion 21a of the pin 21. The upper end of the portion 21a co-operates with the arcuate actuating surface of the rocker arm 20 in such a manner that when the plunger 19 is in its second position the lower end of the pin 21 is flush with the wall of the cavity 17 and when the plunger 19 is in its first position the lower end of the pin 21 protrudes downwardly into the cavity 17.

In use, the paraffin wax material is intermittently forced through the bore 12, so that a tube of the material is extruded step-'by-step forwardly towards the bore of the barrel 10, once for each loom cycle. At the commencement of each picking operation the end of the weft yarn which extends into the unit through the aperture 14 is disposed just forwardly of the hemispherical cavities 17 and 18. The cavity 17 is then moved towards the cavity 18 by the actuating arm 20 to deform the tubular extrusion and compress same to form a spherical pellet on the end of the weft thread. The cavity 17 is then retracted, the operation of the ejector pin 21 ensuring that the pellet is left in engagement with the lower cavity 18. The pellet is aligned with the bore of the barrel 10 by means of a movable pin 23 adapted to lift the pellet from the cavity 18.

The pin 23 extends upwardly through the block assembly 11 to the base of the cavity 18 and is normally urged downwardly by a compression spring 24 but may be moved upwardly against the action of the spring by a cam 25.

A burst of compressed air is then admitted to the chamber 16 to force the pellet forwardly through the barrel 10. The pellet carries the weft thread out from the forward end of the barrel and across the warp shed where it impinges upon a suitable rigid target, and is thereby brought to rest. Owing to the low elasticity of the material from which the pellet has been formed, there is substantially no rebound of the pellet and therefore no danger of the pellet carrying the forward end of the weft thread back into the warp shed. At this stage of the operational cycle the weft thread is pulled back towards the projecting unit to straighten same, and the thread is severed at the selvedges on both sides of the cloth being woven by any suitable means, thereby releasing the pellet, whose material can be reclaimed for re-use. At this stage the weft thread is again pulled back so that its free end is drawn backwardly through the barrel 10 to come to rest at a position just forward of the cavities 17 and 18 ready for the next operational cycle.

The length and wall thickness of the tube of material of high plasticity formed at each extrusion step is selected so that the volume of the extruded length just compresses to form a solid spherical pellet of the required diameter as determined by the cavities 17 and 18.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations such as might readily occur to one skilled in the art being possible without departing from the scope thereof as defined by the appended claims.

What is claimed is:

1. A method of weaving wherein each weft pick is formed by projecting a thread through a warp shed by a carrier jet of a fluid and wherein a pellet is first attached to the leading end of each weft thread, characterised in that each said pellet is produced by extruding a tube of material having plastic properties and low elasticity around the weft thread and subsequently deforming the tube inwardly against the thread.

2. A method according to claim 1 wherein said pellet is formed from a parafiin wax material.

3. A method according to claim 1 wherein each weft thread is projected by a jet of compressed air.

4. A method according to claim 2 wherein each weft thread is projected by a jet of compressed air.

5. Apparatus for projecting successive weft threads through a warp shed in a method of shuttleless weaving comprising a barrel having a bore therethrough a block assembly at the rear of the barrel, an aperture for yarn through said block assembly co-axial with said barrel and communicating with the bore thereof, a chamber in said block assembly having an annular orifice surrounding said aperture for yarn, means for forcing a plastic material having low elasticity into said chamber whereby a tube thereof is extruded around an end of yarn extending from said aperture, reciprocable die means adapted to be actuated to deform said tube of material inwardly against said yarn to form a pellet thereon and means for introducing a fluid under pressure behind said pellet whereby the latter is expelled through said barrel with said end of yarn.

6. Apparatus according to claim 4 wherein said means for introducing fluid under pressure comprises a further chamber in said block assembly having an annular orifice surrounding said first-mentioned annular orifice, and means for connecting said further chamber with a supply of compressed air.

7. Apparatus according to claim 5 wherein said means for deforming the tube comprises oppositely disposed hemispherical cavities adapted to be moved together to form a spherical cavity.

8. Apparatus according to claim 6 wherein said means for deforming the tube comprises oppositely disposed hemisphercial cavities adapted to be moved together to form a spherical cavity.

9. Apparatus according to claim 7 wherein the first of said cavities is fixed such that its diametral plane is tangential to the bore of the barrel, the second of said cavities being formed at one end of a plunger adapted to be reciprocated by rocker-arm means.

10. Apparatus according to claim 8 wherein the first of said cavities is fixed such that its diametral plane is tangential to the bore of the barrel, the second of said cavities being formed at one end of a plunger adapted to be reciprocated by rocker-arm means.

11. Apparatus according to claim 9 wherein said second cavity includes ejector pin means adapted to displace the pellet therefrom after its formation.

12. Apparatus according to claim 10 wherein said second cavity includes ejector pin means adapted to displace the pellet therefrom after its formation.

13. Apparatus according to claim 11 wherein said first cavity includes pin means adapted to be reciprocated to align said pellet with the bore of the barrel after separation of said two cavities.

14. Apparatus according to claim 12 wherein said first cavity includes pin means adapted to be reciprocated to align said pellet with the bore of the barrel after separation of said two cavities.

References Cited UNITED STATES PATENTS 3,095,910 7/1963 Deady et al. 139-127 3,224,468 12/1965 Zerbee 139-127 FOREIGN PATENTS 251,353 9/ 1948 Switzerland.

HENRY S. JAUDON, Primary Examiner. 

